Spectroscopy module

ABSTRACT

In a spectroscopy module  1 , a light passing hole  50  through which a light L 1  advancing to a spectroscopic portion  4  passes is formed in a light detecting element  5 . Therefore, it is possible to prevent the relative positional relationship between the light passing hole  50  and a light detecting portion  5   a  of the light detecting element  5  from deviating. Moreover, the light detecting element  5  is bonded to a front plane  2   a  of a substrate  2  with an optical resin adhesive  63 . Thus, it is possible to reduce a stress generated onto the light detecting element  5  due to a thermal expansion difference between the light detecting element  5  and the substrate  2 . Additionally, on the light detecting element  5 , a first pool portion  101  is formed so as to be located at least between the light detecting portion  5   a  and the light passing hole  50  when viewed from a direction substantially perpendicular to the front plane  2   a . Thus, when the light detecting element  5  is attached to the substrate  2  via the optical resin adhesive  63 , the optical resin adhesive  63  is pooled to remain at the first pool portion  101 . Thus, the optical resin adhesive  63  is prevented from penetrating into the light passing hole  50.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a spectroscopy module for dispersinglight to detect the light.

2. Related Background of the Invention

There is known such a conventional spectroscopy module described in, forexample, Japanese Published Unexamined Patent Application No.H04-294223, Japanese Published Unexamined Patent Application No.2004-354176, and Japanese Published Unexamined Patent Application No.2003-243444. Japanese Published Unexamined Patent Application No.H04-294223 has described a spectroscopy module which is provided with asupporting body through which light is allowed to transmit, an incidentslit portion through which light is made incident into the supportingbody, a concave diffraction grating that disperses the light madeincident into the supporting body to reflect the light, and a diode thatdetects the lights dispersed and reflected by the concave diffractiongrating.

SUMMARY OF THE INVENTION

However, in the spectroscopy module described in Japanese PublishedUnexamined Patent Application No. H04-294223, when the incident slitportion and the diode are attached to the supporting body, the relativepositional relationship between the incident slit portion and the diodemay deviate, thereby degrading the reliability of the spectroscopymodule.

The present invention has been achieved in consideration of theabove-described circumstances, and an object of the present invention isto provide a highly reliable spectroscopy module.

In order to achieve the above-described object, the spectroscopy moduleaccording to the present invention is provided with a body portionthrough which light is allowed to transmit, a spectroscopic portion thatdisperses a light made incident into the body portion from a side of apredetermined plane of the body portion, to reflect lights to the sideof the predetermined plane, a light detecting element which is providedon the predetermined plane, and detects the lights dispersed by thespectroscopic portion, and an optical resin adhesive disposed at leastbetween the predetermined plane and a light detecting portion of thelight detecting element, and in the spectroscopy module, a light passinghole through which a light advancing to the spectroscopic portion passesis formed, and terminal electrodes facing a side opposite to the bodyportion are provided in the light detecting element, and on a plane atthe body portion side of the light detecting element, a first poolportion is formed so as to be located at least between the lightdetecting portion and the light passing hole when viewed from adirection substantially perpendicular to the predetermined plane.

In the spectroscopy module, the light passing hole through which a lightadvancing to the spectroscopic portion passes is formed in the lightdetecting element. Therefore, it is possible to prevent the relativepositional relationship between the light passing hole and the lightdetecting portion of the light detecting element from deviating.Moreover, the light detecting element is attached to the predeterminedplane of the body portion via the optical resin adhesive. Thus, it ispossible to reduce a stress generated onto the light detecting elementdue to a thermal expansion difference between the light detectingelement and the body portion. Additionally, on the plane at the bodyportion side of the light detecting element, the first pool portion isformed so as to be located at least between the light detecting portionand the light passing hole when viewed from a direction substantiallyperpendicular to the predetermined plane. Thus, when the light detectingelement is attached to the body portion via the optical resin adhesive,the optical resin adhesive is pooled to remain at the first poolportion. Therefore, the optical resin adhesive is prevented frompenetrating into the light passing hole. Thus, a light made incidentinto the body portion is prevented from being refracted or diffused bythe optical resin adhesive penetrating into the light passing hole.Therefore, according to the spectroscopy module, it is possible toimprove the reliability.

In the spectroscopy module according to the present invention, a lightabsorbing layer having a first light passing portion through which thelight advancing to the spectroscopic portion passes, and a second lightpassing portion through which the lights advancing to the lightdetecting portion of the light detecting element pass, is preferablyformed on the predetermined plane. In this case, because stray light isprevented from being generated and stray light is absorbed by the lightabsorbing layer, it is possible to prevent stray light from being madeincident into the light detecting portion of the light detectingelement.

In the spectroscopy module according to the present invention, the firstpool portion is preferably an annular groove formed so as to surround alight emitting opening in the light passing hole. In this case, when thelight detecting element is attached to the body portion via the opticalresin adhesive, the optical resin adhesive is made to remain by thefirst pool portion over the entire circumference of the light emittingopening. Therefore, the optical resin adhesive is further prevented frompenetrating into the light passing hole.

In the spectroscopy module according to the present invention, the firstpool portion is preferably an annular groove formed so as to surroundthe first light passing portion when viewed from a directionsubstantially perpendicular to the predetermined plane. In this case,when the light detecting element is attached to the body portion via theoptical resin adhesive, the optical resin adhesive is pooled to remainat the first pool portion. Thus, the optical resin adhesive is preventedfrom penetrating into the first light passing portion of the lightabsorbing layer. Therefore, a light made incident into the body portionis prevented from being refracted or diffused by the optical resinadhesive penetrating into the first light passing portion.

In the spectroscopy module according to the present invention, on aplane at the body portion side of the light detecting element, a secondpool portion is preferably formed so as to be located at a side oppositeto the first pool portion across the light detecting portion when viewedfrom a direction substantially perpendicular to the predetermined plane.In this case, when the light detecting element is attached to the bodyportion via the optical resin adhesive, it is possible to prevent theoptical resin adhesive from flowing out of an end at the side at whichthe second pool portion is formed in the light detecting element.

The spectroscopy module according to the present invention is preferablyfurther provided with a wiring board attached to the predeterminedplane, and in the spectroscopy module, an opening portion into which thelight detecting element is disposed is formed, and a wiring electricallyconnected to the terminal electrodes is provided in the wiring board.According to this configuration, it is possible to block a light that istrying to advance to the spectroscopic portion without passing throughthe light passing hole.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a spectroscopy module as one embodimentaccording to the present invention.

FIG. 2 is a cross sectional view taken along the line II to II shown inFIG. 1.

FIG. 3 is a bottom view of the spectroscopy module of FIG. 1.

FIG. 4 is a perspective view of a light detecting element of thespectroscopy module of FIG. 1.

FIG. 5 is an enlarged sectional view of a main part of the spectroscopymodule of FIG. 1.

FIG. 6 is a cross sectional view of a spectroscopy module as anotherembodiment according to the present invention.

FIG. 7 is an enlarged sectional view of a main part of the spectroscopymodule of FIG. 1.

FIG. 8 is a plan view showing another embodiment of pool portions of thelight detecting element in the spectroscopy module according to thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, a detailed description will be given to preferredembodiments of the present invention by referring to the drawings. It isnoted that in the individual drawings, the same reference letters ornumerals are given to the same and corresponding parts, with overlappingdescription omitted.

FIG. 1 is a plan view of a spectroscopy module as one embodimentaccording to the present invention, and FIG. 2 is a cross sectional viewtaken along the line II to II shown in FIG. 1. As shown in FIG. 1 andFIG. 2, a spectroscopy module 1 is provided with a substrate (bodyportion) 2 through which a light L1 made incident from a side of a frontplane (predetermined plane) 2 a is allowed to transmit, a lens portion(body portion) 3 through which the light L1 made incident into thesubstrate 2 is allowed to transmit, a spectroscopic portion 4 thatdisperses the light L1 made incident into the lens portion 3 to reflectthe light toward the front plane 2 a, and a light detecting element 5that detects lights L2 dispersed and reflected by the spectroscopicportion 4. The spectroscopy module 1 is a micro-spectroscopy module thatdisperses the light L1 into the lights L2 corresponding to a pluralityof wavelengths by the spectroscopic portion 4, and detects the lights L2by the light detecting element 5, thereby measuring the wavelengthdistribution of the light L1, the intensity of a specific wavelengthcomponent, or the like.

The substrate 2 is formed into a rectangular plate shape (with, forexample, an entire length of 15 to 20 mm, a full width of 11 to 12 mm,and a thickness of 1 to 3 mm), from light-transmitting glass such asBK7, Pyrex (registered trademark) and quartz, plastic, or the like. Aresist layer 72 having an opening portion 71 in a cross-sectionallyrectangular shape into which the light detecting element 5 is fitted, isformed on the front plane 2 a of the substrate 2 via a light absorbinglayer 67. A wiring board 51 in a rectangular plate shape, which has anopening portion 51 a in a cross-sectionally rectangular shape in whichthe light detecting element 5 is disposed, is bonded to a front plane 72a of the resist layer 72 with a resin adhesive 53. The wiring board 51is formed into a rectangular plate shape (with, for example, an entirelength of 15 to 20 mm, a full width of 11 to 12 mm, and a thickness of 1to 3 mm), which is substantially the same as that of the substrate 2 soas to be smaller in entire length and full width than the substrate 2,from ceramic, plastic, polyimide, glass epoxy, an inorganic-organichybrid material, silicon, or the like. The opening portion 51 a formedin the wiring board 51 is formed so as to be larger than the openingportion 71 formed in the resist layer 72. A wiring 52 formed of a metalmaterial is provided to the wiring board 51. The wiring 52 has aplurality of pad portions 52 a disposed around the opening portion 51 a,a plurality of pad portions 52 b disposed at the both ends in thelongitudinal direction of the wiring board 51, and a plurality ofconnection portions 52 c that connect the pad portions 52 a and the padportions 52 b which correspond to one another.

In addition, the light absorbing layer 67 formed on the front plane 2 aof the substrate 2 has a light passing hole (a first light passingportion) 67 a through which the light L1 advancing to the spectroscopicportion 4 passes via a light passing hole 50 (which will be describedlater) of the light detecting element 5, and a light passing hole (asecond light passing portion) 67 b through which the lights L2 advancingto a light detecting portion 5 a (which will be described later) of thelight detecting element 5 passes. As a material of the light absorbinglayer 67, colored resin (silicone, epoxy, acrylic, urethane, polyimide,or composite resin, or the like) including black resist or a filler(such as carbon or oxide), metal such as Cr or Co or metal oxidethereof, or a laminated film thereof, or porous-type ceramic, metal, ormetal oxide, can be cited.

FIG. 3 is a bottom view of the spectroscopy module of FIG. 1. As shownin FIGS. 2 and 3, the lens portion 3 is formed into a shape such that asemispherical lens is cut off along two planes substantiallyperpendicular to its bottom plane 3 a and substantially parallel to eachother to form its side planes 3 b (with, for example, a radius of 6 to10 mm, an entire length of the bottom plane 3 a of 12 to 18 mm, a fullwidth of the bottom plane 3 a (i.e., a distance between the side planes3 b) of 6 to 10 mm, and a height of 5 to 8 mm), from a material which isthe same as that of the substrate 2, that is light-transmitting resin, alight-transmitting organic-inorganic hybrid material, orlight-transmitting low-melting point glass or plastic for replicamolding, or the like. The lens portion 3 is bonded to a rear plane 2 bof the substrate 2 with an optical resin adhesive 73 through which thelights L1 and L2 are allowed to transmit by using the outer edge portionof the substrate 2 such as the corners or the sides of the substrate 2as a reference portion. At this time, because the spectroscopic portion4 is positioned with respect to the lens portion 3 with high precision,the outer edge portion of the substrate 2 serves as a reference portionfor positioning the spectroscopic portion 4 at the substrate 2. Inaddition, the lens shape is not limited to a spherical lens, and may bean aspherical lens.

The spectroscopic portion 4 is a reflection type grating having adiffraction layer 6 formed on the outer surface of the lens portion 3, areflection layer 7 formed on the outer surface of the diffraction layer6, and a passivation layer 54 that covers the diffraction layer 6 andthe reflection layer 7. The diffraction layer 6 is formed so that aplurality of grating grooves 6 a are provided adjacent to each otheralong the longitudinal direction of the substrate 2, and the directionin which the grating grooves 6 a are extended is substantially matchedto a direction substantially perpendicular to the longitudinal directionof the substrate 2. For example, a cross-sectionally serrated blazedgrating, a cross-sectionally rectangular binary grating, across-sectionally sinusoidal holographic grating, or the like is appliedas the diffraction layer 6, and the diffraction layer 6 is formed bysubjecting optical resin for replica molding such as photo curing epoxyresin, acryl resin, or organic-inorganic hybrid resin to photo curing.The reflection layer 7 is a membrane form, and is formed by, forexample, evaporating Al, Au, or the like onto the outer surface of thediffraction layer 6. In addition, an optical NA of the spectroscopymodule can be adjusted by adjusting an area on which the reflectionlayer 7 is formed. The passivation layer 54 is a membrane form, and isformed by, for example, evaporating MgF₂, SiO₂, or the like onto theouter surfaces of the diffraction layer 6 and the reflection layer 7.

As shown in FIGS. 1 and 2, the light detecting element 5 is formed intoa rectangular plate shape (with, for example, an entire length of 5 to10 mm, a full width of 1.5 to 3 mm, and a thickness of 0.1 to 0.8 mm).The light detecting portion 5 a is formed on the plane at the side ofthe spectroscopic portion 4 of the light detecting element 5. The lightdetecting portion 5 a is a CCD image sensor, a PD array, or a CMOS imagesensor or the like, and is formed so that a plurality of channels arearrayed in a direction substantially perpendicular to the direction inwhich the grating grooves 6 a of the spectroscopic portion 4 areextended (i.e., the direction in which the grating grooves 6 a areprovided adjacent to each other).

In the case in which the light detecting portion 5 a is a CCD imagesensor, light intensity information at a position at which the light ismade incident into pixels disposed two-dimensionally is subjected toline-binning, and to make the information into light intensityinformation at a one-dimensional position, the light intensityinformation at the one-dimensional position is read out in time-series.That is, a line of the pixels subjected to line-binning becomes onechannel. In the case in which the light detecting portion 5 a is a PDarray or a CMOS image sensor, because light intensity information at aposition at which the light is made incident into pixels disposedone-dimensionally is read out in time-series, one pixel becomes onechannel.

In addition, in the case in which the light detecting portion 5 a is aPD array or a CMOS image sensor, and pixels are arrayedtwo-dimensionally, a line of pixels arrayed in a direction of aone-dimensional array parallel to the direction in which the gratinggrooves 6 a of the spectroscopic portion 4 are extended becomes onechannel. Further, in the case in which the light detecting portion 5 ais a CCD image sensor, for example, a light detecting portion 5 a inwhich a space between channels in its array direction is 12.5 μm, anentire length of a channel (a length of a one-dimensional pixel rowsubjected to line-binning) is 1 mm, and the number of channels to bearrayed is 256 is used for the light detecting element 5.

Further, the light passing hole 50 through which the light L1 advancingto the spectroscopic portion 4 passes, that is provided adjacent to thelight detecting portion 5 a in the array direction of the channels, isformed in the light detecting element 5. The light passing hole 50 is aslit (with, for example, a length of 0.5 to 1 mm and a width of 10 to100 μm) which is extended in a direction substantially perpendicular tothe longitudinal direction of the substrate 2, and is formed by etchingor the like so as to be positioned with high precision with respect tothe light detecting portion 5 a.

FIG. 4 is a perspective view of the light detecting element of thespectroscopy module of FIG. 1. FIG. 5 is an enlarged sectional view of amain part of the spectroscopy module of FIG. 1. As shown in FIGS. 4 and5, a first pool portion 101 is formed so as to surround a light emittingopening 50 b in a plane at the side of the substrate 2 of the lightdetecting element 5. As shown in FIG. 4, the first pool portion 101 is arectangular annular groove. Further, the first pool portion 101 isformed so as to surround the light passing hole 67 a when viewed from adirection substantially perpendicular to the front plane 2 a of thesubstrate 2. Moreover, a second pool portion 102 is formed into a planeat the side of the substrate 2 of the light detecting element 5. Thesecond pool portion 102 is formed so as to be located at the sideopposite to the first pool portion 101 across the light detectingportion 5 a when viewed from a direction substantially perpendicular tothe front plane 2 a of the substrate 2. In this case, the second poolportion 102 is a linear groove.

As shown in FIGS. 1 and 5, a plurality of electrodes 58 are formed onthe plane at the side of the substrate 2 of the light detecting element5, and a plurality of terminal electrodes 61 connected to the respectiveelectrodes 58 via feed-through electrodes 59 are formed on the planeopposite to the substrate 2 of the light detecting element 5. Therespective terminal electrodes 61 facing the side opposite to thesubstrate 2 are connected to the corresponding pad portions 52 a of thewiring board 51 with wires 62. Thereby, the terminal electrodes 61 andthe wiring 52 are electrically connected, and electric signals generatedin the light detecting portion 5 a are led to the outside via theelectrodes 58, the feed-through electrodes 59, the terminal electrodes61, the pad portions 52 a, connection portions 52 c, and the padportions 52 b.

As shown in FIG. 5, the light detecting element 5 is fitted into theopening portion 71 of the resist layer 72, and is bonded to the frontplane 2 a of the substrate 2 with an optical resin adhesive 63 throughwhich the lights L1 and L2 are allowed to transmit. The opening portion71 is formed by etching so as to have a predetermined positionalrelationship with respect to the outer edge portion of the substrate 2serving as a reference portion for positioning the spectroscopic portion4 to the substrate 2. In addition, the light detecting element 5 isprojected from the front plane 72 a of the resist layer 72 while beingfitted into the opening portion 71.

In the spectroscope module 1 configured as described above, the light L1is made incident into the substrate 2 from the side of the front plane 2a of the substrate 2 via the light passing hole 50 of the lightdetecting element 5 and the light passing hole 67 a of the lightabsorbing layer 67, and advances inside the substrate 2, the opticalresin adhesive 73, and the lens portion 3, to reach the spectroscopicportion 4. The light L1 reaching the spectroscopic portion 4 isdispersed into lights L2 corresponding to a plurality of wavelengths bythe spectroscopic portion 4. The dispersed lights L2, are not onlydispersed by the spectroscopic portion 4, but also reflected toward thefront plane 2 a of the substrate 2, and advance inside the lens portion3, the optical resin adhesive 73, and the substrate 2 to reach the lightdetecting portion 5 a of the light detecting element 5 via the lightpassing hole 67 b of the light absorbing layer 67 and the optical resinadhesive 63. The lights L2 reaching the light detecting portion 5 a aredetected by the light detecting element 5.

A method for manufacturing the spectroscopy module 1 described abovewill be described.

First, the spectroscopic portion 4 is formed on the lens portion 3. Indetail, a light-transmitting master grating on which gratingscorresponding to the diffraction layer 6 are engraved is pushed onto theoptical resin for replica molding falling in drops near the tip of thelens portion 3. Then, the optical resin for replica molding is subjectedto light in this state to cure the optical resin for replica molding,and the optical resin for replica molding is preferably subjected tothermal curing for stabilization, to form the diffraction layer 6 havingthe plurality of grating grooves 6 a. Thereafter, the master grating isdemolded, and μl, Au, or the like is evaporated with a mask or isentirely evaporated onto the outer surface of the diffraction layer 6 toform the reflection layer 7. Moreover, MgF₂, SiO₂, or the like isevaporated with a mask or is entirely evaporated onto the outer surfacesof the diffraction layer 6 and the reflection layer 7 to form thepassivation layer 54.

Meanwhile, the substrate 2 is prepared, and the light absorbing layer 67having the light passing holes 67 a and 67 b is formed on the frontplane 2 a of the substrate 2. Moreover, the resist layer 72 having theopening portion 71 is formed on the front plane 2 a of the substrate 2via the light absorbing layer 67. In addition, the opening portion 71 isformed by etching so as to have a predetermined positional relationshipwith respect to the outer edge portion of the substrate 2 serving as areference portion for positioning the spectroscopic portion 4 to thesubstrate 2.

Next, the optical resin adhesive 63 is applied onto the front plane 2 aof the substrate 2 exposed in the opening portion 71 of the resist layer72, and the light detecting element 5 in which the first pool portion101 and the second pool portion 102 are formed is fitted into theopening portion 71, to be pressed onto the front plane 2 a of thesubstrate 2. At this time, the optical resin adhesive is pooled toremain at the first pool portion 101 and the second pool portion 102.Then, the optical resin adhesive 63 is subjected to light to be cured,and the light detecting element 5 is mounted onto the substrate 2.Thereafter, the lens portion 3 on which the spectroscopic portion 4 isformed is bonded to the rear plane 2 b of the substrate 2 with theoptical resin adhesive 73 by using the outer edge portion of thesubstrate 2 as a reference portion.

Next, the wiring board 51 is bonded to the front plane 72 a of theresist layer 72 with the resin adhesive 53. Then, the terminalelectrodes 61 of the light detecting element 5 and the pad portions 52 aof the wiring board 51 which correspond to one another are connectedwith the wires 62, to obtain the spectroscopy module 1.

As described above, in the spectroscopy module 1, the light passing hole50 through which the light L1 advancing to the spectroscopic portion 4passes, is formed in the light detecting element 5. Therefore, it ispossible to prevent the relative positional relationship between thelight passing hole 50 and the light detecting portion 5 a of the lightdetecting element 5 from deviating. Moreover, the light detectingelement 5 is bonded to the front plane 2 a of the substrate 2 with theoptical resin adhesive 63. Thus, it is possible to reduce a stressgenerated onto the light detecting element 5 due to a thermal expansiondifference between the light detecting element 5 and the substrate 2.Additionally, on the plane at the side of the substrate 2 of the lightdetecting element 5, the first pool portion 101 is formed so as to belocated between the light detecting portion 5 a and the light passinghole 50 when viewed from a direction substantially perpendicular to thefront plane 2 a of the substrate 2. Thus, when the light detectingelement 5 is attached to the substrate 2 via the optical resin adhesive63, the optical resin adhesive 63 is pooled to remain at the first poolportion 101. Therefore, the optical resin adhesive 63 is prevented frompenetrating into the light passing hole 50. Therefore, a light madeincident into the substrate 2 is prevented from being refracted ordiffused by the optical resin adhesive penetrating into the lightpassing hole 50. Here, the first pool portion 101 is an annular grooveformed so as to surround the light emitting opening 50 b. Therefore,when the light detecting element 5 is attached to the substrate 2 viathe optical resin adhesive 63, the optical resin adhesive is made toremain by the first pool portion over the entire circumference of thelight emitting opening. Thus, the optical resin adhesive 63 is furtherprevented from penetrating into the light passing hole. Additionally,the first pool portion 101 is formed so as to surround the light passinghole 67 a when viewed from a direction substantially perpendicular tothe front plane 2 a of the substrate 2. Thus, when the light detectingelement 5 is attached to the substrate 2 via the optical resin adhesive63, the optical resin adhesive 63 is pooled to remain at the first poolportion 101. Thus, the optical resin adhesive 63 is prevented frompenetrating into the light passing hole 67 a. Therefore, a light madeincident into the substrate 2 is prevented from being refracted ordiffused by the optical resin adhesive penetrating into the lightpassing hole 67 a. Further, on the plane at the side of the substrate 2of the light detecting element 5, the second pool portion 102 is formedso as to be located at the side opposite to the first pool portion 101across the light detecting portion 5 a when viewed from a directionperpendicular to the front plane 2 a of the substrate 2. Therefore, theoptical resin adhesive 63 is prevented from flowing out of the end atthe side at which the second pool portion 102 is formed in the lightdetecting element 5. Therefore, according to the spectroscopy module 1,it is possible to improve the reliability.

Further, in the spectroscopy module 1, the light absorbing layer 67having the light passing hole 67 a through which the light L1 advancingto the spectroscopic portion 4 passes and the light passing hole 67 bthrough which the lights L2 advancing to the light detecting portion 5 aof the light detecting element 5 passes, is formed on the front plane 2a of the substrate 2. Because the light absorbing layer 67 preventsgeneration of stray light and absorbs stray light, it is possible toprevent stray light from being made incident into the light detectingportion 5 a.

Further, in the spectroscopy module 1, the wiring board 51 having thewiring 52 electrically connected to the terminal electrodes 61 of thelight detecting element 5 is bonded to the front plane 2 a of thesubstrate 2 in a state in which the light detecting element 5 isdisposed in the opening portion 51 a. According to the wiring board 51,it is possible to block a light that is trying to advance to thespectroscopic portion 4 without passing through the light passing hole50.

Further, in the spectroscopy module 1, because the opening portion 71 ofthe resist layer 72 has a predetermined positional relationship withrespect to the outer edge portion of the substrate 2 serving as areference portion for positioning the spectroscopic portion 4 to thesubstrate 2, the light detecting element 5 is positioned to thesubstrate 2 by merely fitting the light detecting element 5 into theopening portion 71. At this time, because the lens portion 3 on whichthe spectroscopic portion 4 is formed is positioned to the substrate 2in accordance with the outer edge portion of the substrate 2 serving asa reference portion, as a result, alignment of the spectroscopic portion4 and the light detecting element 5 is achieved. Therefore, it ispossible to simply assemble the module while maintaining thereliability.

Further, in the spectroscopy module 1, the light detecting element 5 isprojected from the front plane 72 a of the resist layer 72 while beingfitted into the opening portion 71. Thereby, it is possible, not only tomake a work of fitting the light detecting element 5 into the openingportion 71 provided in the front plane 72 a of the resist layer 72 easy,but also to reliably allow excess resin or air out by reliably pressingthe light detecting element 5 onto the front plane 2 a of the substrate2 exposed in the opening portion 71.

The present invention is not limited to the above-described embodiment.

For example, as shown in FIG. 6, the light absorbing layer 67 having thelight passing hole 67 a through which the light L1 advancing to thespectroscopic portion 4 passes and the light passing hole 67 b throughwhich the lights L2 advancing to the light detecting portion 5 a of thelight detecting element 5 passes, may be formed between the substrate 2and the lens portion 3. According to this configuration, it is possiblefor the light advancing while spreading to be limited so as to reach adesired area, and it is possible to effectively prevent stray light frombeing made incident into the light detecting element 5. Further, it ispossible to adjust an optical NA by differing the sizes of the lightpassing holes 67 a and 67 b in the light absorbing layer 67.

Further, as shown in FIG. 6, a so-called back-illuminated type elementmay be applied as the light detecting element 5. In this case, becausethe electrodes 58 are located outside along with the light detectingportion 5 a, the electrodes 58 may be used as terminal electrodes facingthe side opposite to the substrate 2, and the electrodes 58 may beconnected with the wiring 52 and the wires 62 provided to the frontplane 2 a of the substrate 2.

Further, it is not necessary to provide a portion into which the lightdetecting element 5 is fitted, to the substrate 2 by forming the resistlayer 72 or the like. For example, as shown in FIG. 6, the module may beconfigured such that the light detecting element 5 is attached to thefront plane 2 a of the substrate 2 via the optical resin adhesive 63.Moreover, the substrate 2 and the lens portion 3 may be integrallyformed with a mold, and the lens portion 3 and the diffraction layer 6may be integrally formed of light-transmitting low-melting point glassfor replica molding or the like.

Here, as shown in FIG. 7A, the light detecting element 5 may besubjected to an etching process to form the first pool portion 101 andthe second pool portion 102 integrally with the light detecting element5, or as shown in FIG. 7B, patterning may be applied to the lightdetecting element 5 with permanent resist, metal, or insulator, etc., toform the first pool portion 101 and the second pool portion 102separately from the light detecting element 5.

Further, the first pool portion 101 is a rectangular annular groove inthe present embodiment. However, the first pool portion 101 is notlimited to the shape. For example, as shown in FIG. 8A, the first poolportion 101 may be a linear groove formed so as to separate the lightemitting opening 50 b and the light detecting portion 5 a when viewedfrom a direction substantially perpendicular to the front plane 2 a ofthe substrate 2. Moreover, as shown in FIG. 8B, the first pool portion101 may be a linear groove formed so as to separate the light emittingopening 50 b and the light detecting portion 5 a, and surround the lightemitting opening 50 b when viewed from a direction substantiallyperpendicular to the front plane 2 a of the substrate 2. Further, theshapes of the first pool portion 101 and the second pool portion 102when viewed from a direction substantially perpendicular to the frontplane 2 a of the substrate 2 are not limited to linear shapes, and maybe curved shapes. For example, the second pool portion 102 may be alaterally-facing U-shaped groove curved so as to surround the lightdetecting portion 5 a. Moreover, the first pool portion 101 may beformed at least between the light detecting portion 5 a and the lightpassing hole 50 when viewed from a direction substantially perpendicularto the front plane 2 a of the substrate 2.

In accordance with the present invention, it is possible to improve thereliability of the spectroscopy module.

1. A spectroscopy module comprising: a body portion through which lightis allowed to transmit; a spectroscopic portion that disperses a lightmade incident into the body portion from a side of a predetermined planeof the body portion, to reflect lights to the side of the predeterminedplane; a light detecting element which is provided on the predeterminedplane, the light detecting element detects the lights dispersed by thespectroscopic portion; and an optical resin adhesive disposed at leastbetween the predetermined plane and a light detecting portion of thelight detecting element, wherein, a light passing hole through which alight advancing to the spectroscopic portion passes is formed, andterminal electrodes facing a side opposite to the body portion areprovided in the light detecting element, and on a plane at the bodyportion side of the light detecting element, a first pool portion isformed so as to be located at least between the light detecting portionand the light passing hole when viewed from a direction substantiallyperpendicular to the predetermined plane.
 2. The spectroscopy moduleaccording to claim 1, wherein a light absorbing layer having a firstlight passing portion through which the light advancing to thespectroscopic portion passes, and a second light passing portion throughwhich the lights advancing to the light detecting portion of the lightdetecting element pass, is formed on the predetermined plane.
 3. Thespectroscopy module according to claim 1, wherein the first pool portionis an annular groove formed so as to surround a light emitting openingin the light passing hole.
 4. The spectroscopy module according to claim2, wherein the first pool portion is an annular groove formed so as tosurround the first light passing portion when viewed from a directionsubstantially perpendicular to the predetermined plane.
 5. Thespectroscopy module according to claim 1, wherein, on a plane at thebody portion side of the light detecting element, a second pool portionis formed so as to be located at a side opposite to the first poolportion across the light detecting portion when viewed from a directionsubstantially perpendicular to the predetermined plane.
 6. Thespectroscopy module according to claim 1, further comprising a wiringboard attached to the predetermined plane, wherein an opening portioninto which the light detecting element is disposed is formed, and awiring electrically connected to the terminal electrodes is provided inthe wiring board.